格式化的打印输出

#include<stdio.h>
#include<stdarg.h>

#define LOG_NONE          (-1)
#define LOG_ERROR          0
#define LOG_WARNING        1
#define LOG_INFO           2
#define LOG_DEBUG          3

void sky_log( const char *name, int i_level, const char *fmt, ... )
{
    char *s_level;
    switch( i_level )
    {
        case LOG_ERROR:
            s_level = "error";
            break;
        case LOG_WARNING:
            s_level = "warning";
            break;
        case LOG_INFO:
            s_level = "info";
            break;
        case LOG_DEBUG:
            s_level = "debug";
            break;
        default:
            s_level = "unknown";
            break;
    }

    //将格式化的内容先输出到缓冲区中
    fprintf(stderr, "%s [%s]: ", name, s_level);

    var_list var;

    va_start(var, fmt);

    vfprintf(stderr,fmt, arg);

    va_end(var);

}

int main()

{

    const char * test = "test";

    sky_log("sky", 0, "hello vfprintf %s", test);

    return 1;

}